Scanning Film

I have an Espon 4180 flatbed film scanner that I am happy with. I am
scanning Fuji negative film at 24bit - 3200 dpi. I then edit and crop
the results in Photoshop. Sometimes I crop a horizontal photo to print
as a portrait. In that instance the cropping is severe.

I want to be able to print at least as large as 8x10 and occasionally 11x14.

The scanning takes a long time. I also have to reduce the pixel count
to print on my 1200 dpi Canon IP4000 printer.

QUESTION: Is it necessary to scan at 3200 dpi or can I get the same
results with much lower dpi. If so what is the best dpi to scan without
loosing any quality in the above situation.

In article <WzkFd.1208$8Z1.928@newssvr14.news.prodigy.com>,
measekite@yahoo.com says...
>
>
>I have an Espon 4180 flatbed film scanner that I am happy with. I am
>scanning Fuji negative film at 24bit - 3200 dpi. I then edit and crop
>the results in Photoshop. Sometimes I crop a horizontal photo to print
>as a portrait. In that instance the cropping is severe.
>
>I want to be able to print at least as large as 8x10 and occasionally 11x14.
>
>The scanning takes a long time. I also have to reduce the pixel count
>to print on my 1200 dpi Canon IP4000 printer.
>
>QUESTION: Is it necessary to scan at 3200 dpi or can I get the same
>results with much lower dpi. If so what is the best dpi to scan without
>loosing any quality in the above situation.


Yes, you say you are printing 8x10 and 11x14 inches from extremely cropped 35
mm film, so yes, you need all of 3200 dpi. More would likely be good.

Digital images are dimensioned in pixels, and the actual requirement to print
8x10 inches at say 300 dpi is that you need
(8 inches x 300 dpi) x (10 inches x 300 dpi) = 2400 x 3000 pixels.

Another way to look at it is that the ratio of
(scanning resolution / printing resolution) is the enlargement factor.

8x12 inches is about 9x the size of full frame 35 mm film,
meaning, scan at 2700 dpi, print at 300 dpi, for 2700/300 = 9x size.

But if you are cropping, then the enlargement is much greater than 9x.
Regardless, to print 8x10 inches at 300 dpi, you need 2400 x 3000 pixels.
No matter the starting point, you need have 2400x3000 pixels left for this
goal of printing 8x10 at 300 dpi. If you dont have that much left, then you
can only print it at lower quality than 300 dpi.

And to print 6x4 inches at 300 dpi needs 1800x1200 pixels.

Which is a lesser size requirement, except that if the 6x4 inches might be
cropped from half film width and half film length, then the enlargement is
double that to print 8x12 inches from full frame, meaning you need the same
starting point (number of pixels) to be able to crop this extremely, and
still end up at 1800x1200 pixels.

You didnt mention pixels, and I fear you may not be thinking in pixels,
but pixels is what it is about, pixels is all there is. When we print at say
300 dpi, it has the meaning that we need 300 pixels per inch of dimension.

--
Wayne
http://www.scantips.com "A few scanning tips"

Wayne Fulton wrote:
> You didnt mention pixels, and I fear you may not be thinking in pixels,
> but pixels is what it is about, pixels is all there is. When we print at say
> 300 dpi, it has the meaning that we need 300 pixels per inch of dimension.

One could quibble about the distinction between pixels-per-inch (ppi)
and dots-per-inch (dpi), if one wanted to be really pedantic here. And
it may even be relevant; printing on a 300dpi printer means that we're
printing at much less than 300ppi, since the printer uses several dots
to print each pixel -- though I presume you meant printing at 300ppi.

- Brooks


--
The "bmoses-nospam" address is valid; no unmunging needed.

On Thu, 13 Jan 2005 01:57:10 GMT, measekite <measekite@yahoo.com>
wrote:

> the results in Photoshop. Sometimes I crop a horizontal photo to print
> as a portrait. In that instance the cropping is severe.
>
> I want to be able to print at least as large as 8x10 and occasionally 11x14.

> QUESTION: Is it necessary to scan at 3200 dpi or can I get the same
> results with much lower dpi. If so what is the best dpi to scan without
> loosing any quality in the above situation.

Lets do the math for your worst case...

Assume at least 200dpi for printout.
11x14 = 2200x2800
Assume you crop your portrait picture to the full height of the
35mm original.
you need 2800 pixels minimum on the short side.

So yep 3200 looks like a safe setting.
Try it at 300dpi for printing and 3200 isn't even close...

Alan G.

Author of the Learn to Program website
http://www.freenetpages.co.uk/hp/alan.gauld

I have been printing at 1200 dpi on my Canon IP4000. Are you saying
that I can get just as good results (after scanning at 3200dpi) by
printing at 300 dpi instead of 1200??

Wayne Fulton wrote:

>In article <WzkFd.1208$8Z1.928@newssvr14.news.prodigy.com>,
>measekite@yahoo.com says...
>
>
>>I have an Espon 4180 flatbed film scanner that I am happy with. I am
>>scanning Fuji negative film at 24bit - 3200 dpi. I then edit and crop
>>the results in Photoshop. Sometimes I crop a horizontal photo to print
>>as a portrait. In that instance the cropping is severe.
>>
>>I want to be able to print at least as large as 8x10 and occasionally 11x14.
>>
>>The scanning takes a long time. I also have to reduce the pixel count
>>to print on my 1200 dpi Canon IP4000 printer.
>>
>>QUESTION: Is it necessary to scan at 3200 dpi or can I get the same
>>results with much lower dpi. If so what is the best dpi to scan without
>>loosing any quality in the above situation.
>>
>>
>
>
>Yes, you say you are printing 8x10 and 11x14 inches from extremely cropped 35
>mm film, so yes, you need all of 3200 dpi. More would likely be good.
>
>Digital images are dimensioned in pixels, and the actual requirement to print
>8x10 inches at say 300 dpi is that you need
>(8 inches x 300 dpi) x (10 inches x 300 dpi) = 2400 x 3000 pixels.
>
>Another way to look at it is that the ratio of
>(scanning resolution / printing resolution) is the enlargement factor.
>
>8x12 inches is about 9x the size of full frame 35 mm film,
>meaning, scan at 2700 dpi, print at 300 dpi, for 2700/300 = 9x size.
>
>But if you are cropping, then the enlargement is much greater than 9x.
>Regardless, to print 8x10 inches at 300 dpi, you need 2400 x 3000 pixels.
>No matter the starting point, you need have 2400x3000 pixels left for this
>goal of printing 8x10 at 300 dpi. If you dont have that much left, then you
>can only print it at lower quality than 300 dpi.
>
>And to print 6x4 inches at 300 dpi needs 1800x1200 pixels.
>
>Which is a lesser size requirement, except that if the 6x4 inches might be
>cropped from half film width and half film length, then the enlargement is
>double that to print 8x12 inches from full frame, meaning you need the same
>starting point (number of pixels) to be able to crop this extremely, and
>still end up at 1800x1200 pixels.
>
>You didnt mention pixels, and I fear you may not be thinking in pixels,
>but pixels is what it is about, pixels is all there is. When we print at say
>300 dpi, it has the meaning that we need 300 pixels per inch of dimension.
>
>
>

In article <a4AFd.10948$5R.2403@newssvr21.news.prodigy.com>,
measekite@yahoo.com says...
>
>
>I have been printing at 1200 dpi on my Canon IP4000. Are you saying
>that I can get just as good results (after scanning at 3200dpi) by
>printing at 300 dpi instead of 1200??

Absolutely. Try it and you'll see. However scanning at 3200 dpi and
printing at 300 dpi will give 3200/300 = 10.7X enlargement, about 10x15 inches
from full frame 35 mm, which wont be very appropriate for that 6x4 inch
printer, unless you crop the daylights out of it. You need more like 4.4x
enlargement for 6x4 from full frame 35 mm, and of course more if you crop
much.

Let's be sure we are on the same page however. When I say "print at 300 dpi",
I mean that to print 6 inches, you must have (6 inches x 300 dpi) = 1800
pixels in that image dimension. 1800 pixels will print 6 inches at 300 dpi.
This 300 dpi value is scaled (or set) in a photo editor program. That resize
dialog shows you have 1800 pixels, and you might specify either the 6 inches
or the 300 dpi there, and it does the division to compute the other. Then you
print it at 300 dpi. The image properties will say this 300 dpi value then,
which is how it gets 6 inches from 1800 pixels. I refer to that image
property.

And very important, you must still have 1800 pixels after this resize if you
are scaling instead of resampling. Photo programs do vary, but many of them
today have a RESAMPLE check box there (resize dialog) which you turn off to
scale instead of resample. This is very basic, and extremely important, be
certain that you understand the difference between scaling and resampling. It
is the one required fundamental fact about printing digital images.
My site below might help.

However, the printer driver Properties also has a box for dpi, which has a
different meaning of dpi. I am not speaking of that, but I was not sure if
you were or not, hence all of this. That printer dpi rating Property is about
ink dots instead of image pixels. The 1200 dpi is in that context, but the 300
dpi is in the first context above. In this printer driver Properties, you
might be able to set maybe 300 dpi to select fast draft mode (but poor
quality), or a slower but better 1200 dpi photo quality mode. This setting is
about the print quality. So I dont mean that.

You do want to print a 300 dpi image printed to maybe a 1200 dpi printer
quality setting, asssuming you want photo quality.

Because, the 1200 dpi printer rating is not about pixels, but instead about
where the printer can position its ink dots of 3 or 5 colors of ink. 24 bit
pixels can have up to 16.7 million colors. One of those possible 16.7 million
colors for one pixel might be pink. You dont have any pink ink. You dont even
have any red ink. So pink must be simulated by several ink dots of only 3 or
5 colors of CMYK ink, so that that the total appearance averages out near the
correct color. Because of this need for several ink dots per pixel, there is
no way a 1200 dpi printer can reproduce a 1200 dpi color image properly.
However (the one exception), it could print 1200 dpi line art images, because
line art is only two colors, black or white, and the printer has ink that is
exactly black, and the paper is exactly white, so that one ink dot can
represent one pixel if line art. But no way for color.

Sorry to be wordy, and I'm not even sure if this was related to your question,
but the short of it is that the term dpi has two standard meanings :

If about image resolution, dpi means pixels per inch. This is a very old
term, it has always been true, since long before ink jets had color ink to
worry about. The newcomers often dont know this, so recently dpi is also being
called ppi to help understand it, and that's fine, it is very descriptive.
However you will see dpi everywhere, and ppi in only relatively few places.
So, we must understand it both ways. Dpi and ppi have exactly the same
meaning in this context (about images, not printers).

If about printer ratings, dpi means ink drops per inch, of one color of ink.
That is something entirely different, not about pixels at all.

One knows the difference by the context in which it is used. It is not
difficult, it always means the only thing it can mean, in context.

Hope that helps.

--
Wayne
http://www.scantips.com "A few scanning tips"

In article <41e6f157$0$16110$8b463f8a@news.nationwide.net>, Wayne Fulton
<nospam@invalid.com> writes
>In article <a4AFd.10948$5R.2403@newssvr21.news.prodigy.com>,
>measekite@yahoo.com says...
>>
>>
>>I have been printing at 1200 dpi on my Canon IP4000. Are you saying
>>that I can get just as good results (after scanning at 3200dpi) by
>>printing at 300 dpi instead of 1200??
>
>Absolutely. Try it and you'll see.

Err - I don't think so Wayne!

I know that you know that printing at 300 "dots-per-inch" makes the ink
dots very visible indeed. ;-)

I know that you know that Measekit will get vastly superior results
printing at 1200dpi than printing at 300dpi. ;-)

However, he will see very little difference printing at 300ppi
(PIXELS-per-inch) compared to printing at 1200ppi and I think that is
what you mean, but it isn't what Measekit asked.

I know that you know the difference between the two, and Brooks already
raised the distinction in this thread, but his question clearly shows
that Measekit doesn't understand that distinction. It won't help his
understanding by further confusing the terms. He should continue to
print at 1200dpi on the printer because that is the minimum decent
setting for photo quality from his printer. However, there is generally
no value in him printing at more than 300ppi.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

Arguing the semantics of the term isnt going to get it done Kennedy, since
the term has multiple definitions. I wasnt sure which way measekite meant
it, so that's why I tried to explain both accounts.

--
Wayne
http://www.scantips.com "A few scanning tips"

In article <41e73066$0$16107$8b463f8a@news.nationwide.net>, Wayne Fulton
<nospam@invalid.com> writes
>Arguing the semantics of the term isnt going to get it done Kennedy, since
>the term has multiple definitions.
>
It only has one definition, but it is frequently misused, even by
manufacturers and software writers, and hence often misunderstood by
users. That is why it is important that we try to get it right when
explaining the issue to those who are new to the game and only have the
instruction manual for one particular piece of equipment to go on.

Dots are not pixels and pixels are not dots, it is as simple as that.
You can call it what you like, but avoiding those semantics is simply
promoting continued confusion - otherwise you might as well use german
terminology in one paragraph, greek in the next and swahili in a third.
What you call semantics is actually what makes a common language useful.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)

"Kennedy McEwen" <rkm@nospam.demon.co.uk> wrote in message
news:48XEwMDpe45BFwy5@kennedym.demon.co.uk...
> In article <41e73066$0$16107$8b463f8a@news.nationwide.net>, Wayne
> Fulton <nospam@invalid.com> writes
>>Arguing the semantics of the term isnt going to get it done Kennedy,
>>since
>>the term has multiple definitions.
>>
> It only has one definition, but it is frequently misused, even by
> manufacturers and software writers, and hence often misunderstood by
> users. That is why it is important that we try to get it right when
> explaining the issue to those who are new to the game and only have
> the instruction manual for one particular piece of equipment to go
> on.
>
> Dots are not pixels and pixels are not dots, it is as simple as
> that. You can call it what you like, but avoiding those semantics is
> simply promoting continued confusion - otherwise you might as well
> use german terminology in one paragraph, greek in the next and
> swahili in a third. What you call semantics is actually what makes a
> common language useful.

I fully agree with that. Pixels are not dots. Life will become so much
easier if terminology is used correctly. It will help newbies in
understanding, and it'll help the more experienced posters by not
having to explain it over and over again (at least not as often).

There are samples and pixels (SPI or PPI) on the one side, and on the
other side there are (multiple) printer (ink) dots (DPI) that are used
to simulate intermediate ink colors for each pixel (through a process
called dithering). The samples or pixels define the spatial resolution
limit, the dots define intermediate (ink) color accuracy.

Bart